I've got our bi-folds open at the moment, they're east facing, but we have floor to ceiling south facing and west facing windows too.
There are currently about 150 flying things sat on those south facing, non-bi fold windows.
On days where I only open 1/5th of the door, I get about 1/4rd the flies, and at least 1 wasp.
On days where I open all the bi-folds, I get 5 wasps and 150 flying things.
HOWEVER
I am surrounded by large shrubs and 50ft from a river, which makes an awfully big difference to the level of critters you get. There are clouds of the buggers outside all day long right now.
If you don't want to evict wasps AND hate flies, don't get bi-folds! Unless you live somewhere where nothing green grows.
That said, they're all dumb. They sit on the south facing windows getting baked by the sun all day and at the end of the day most of them die from heat exhaustion. I get a lot of floor debris.
The flying things generally aren't problematic because all they're interested in doing is sunbathing and then dying.